Comparative Pharmacology
Head-to-head clinical analysis: ALLEGRA D 12 HOUR ALLERGY AND CONGESTION versus ALLEGRA D 24 HOUR ALLERGY AND CONGESTION.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ALLEGRA D 12 HOUR ALLERGY AND CONGESTION versus ALLEGRA D 24 HOUR ALLERGY AND CONGESTION.
ALLEGRA-D 12 HOUR ALLERGY AND CONGESTION vs ALLEGRA-D 24 HOUR ALLERGY AND CONGESTION
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fexofenadine is a selective peripheral H1-receptor antagonist; pseudoephedrine is a sympathomimetic amine that directly stimulates alpha-adrenergic receptors, causing vasoconstriction and decongestion.
Fexofenadine is a selective peripheral H1-receptor antagonist that inhibits histamine release from mast cells. Pseudoephedrine is a sympathomimetic amine that directly stimulates alpha-adrenergic receptors in the respiratory tract mucosa, causing vasoconstriction and reducing nasal congestion. It also has weak beta-adrenergic activity.
Adults and children 12 years and older: 1 tablet (fexofenadine 60 mg/pseudoephedrine 120 mg) orally every 12 hours with water. Do not exceed 2 tablets in 24 hours.
1 tablet (fexofenadine 180 mg / pseudoephedrine 240 mg) orally every 24 hours.
None Documented
None Documented
Fexofenadine: 14.4 hours in healthy adults (range 11-15 h); pseudoephedrine: 5-8 hours (pH-dependent urinary excretion may prolong to 14-16 h in alkaline urine).
Fexofenadine: terminal half-life 14.4 hours (range 11-17 h, ~4-fold longer than IV due to enterohepatic recirculation); pseudoephedrine: terminal half-life 4.3-8 hours (alkaline urine prolongs to 16 h).
Fexofenadine: 95% excreted unchanged in feces (biliary) and 5% in urine. Pseudoephedrine: 90% excreted unchanged in urine; remainder undergoes hepatic N-demethylation.
Fexofenadine: ~95% excreted unchanged in feces (80%) and urine (11-12%); pseudoephedrine: ~70-90% excreted unchanged in urine (major route).
Category C
Category C
Antihistamine-Decongestant Combination
Antihistamine-Decongestant Combination